On Thu, Feb 13, 2014 at 10:27:01AM -0800, Greg KH wrote: > On Thu, Feb 13, 2014 at 06:15:59PM +0000, Russell King - ARM Linux wrote: > > On Thu, Feb 13, 2014 at 10:12:16AM -0800, Greg KH wrote: > > > On Mon, Jan 20, 2014 at 10:04:15AM +0000, Russell King - ARM Linux wrote: > > > > On Mon, Jan 20, 2014 at 02:32:35PM +0530, Tushar Behera wrote: > > > > > uart_register_driver call binds the driver to a specific device > > > > > node through tty_register_driver call. This should typically happen > > > > > during device probe call. > > > > > > > > > > In a multiplatform scenario, it is possible that multiple serial > > > > > drivers are part of the kernel. Currently the driver registration fails > > > > > if multiple serial drivers with same default major/minor numbers are > > > > > included in the kernel. > > > > > > > > > > A typical case is observed with amba-pl011 and samsung-uart drivers. > > > > > > > > NAK. There should not be any other driver using amba-pl011's device numbers. > > > > > > I agree, but there is. And because of that, moving the registration to > > > the probe call fixes the issue with building a kernel with all of the > > > drivers built into them, so I'm going to take both of these patches, as > > > it does solve that problem, while still allowing the device number > > > collision to happen. > > > > So what happens when two _devices_ are probed by this driver at the same > > time? > > The bus that the driver is on will not allow that to happen, I thought > we went through this before... > > And yes, devices on different busses could cause problems, but is that > the case here for these devices? At first glance, I don't think that > can happen for these drivers. We went through this before, and I stated the paths, and no one disagreed with that. It /is/ racy. -- FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad. Estimate before purchase was "up to 13.2Mbit". -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
